## Common ground
All options are weight screws made from different metallic materials.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Made from ferrous metal, typically the most common and cost-effective material.
- **Typical examples:** Standard machine screws, industrial fasteners.
- **Best fit when:** Budget-friendly, high-strength applications in general engineering.
**7415.33 – Copper**
- **Defining trait:** Non-ferrous, electrically conductive, and corrosion-resistant.
- **Typical examples:** Electrical connectors, marine hardware.
- **Best fit when:** Requires conductivity or resistance to corrosion in moist environments.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and heat resistance; often used for durability.
- **Typical examples:** Aerospace components, chemical equipment fasteners.
- **Best fit when:** Exposure to harsh chemicals or high temperatures.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with good corrosion resistance.
- **Typical examples:** Aircraft parts, consumer electronics.
- **Best fit when:** Weight reduction is critical and strength needs are moderate.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (galvanizing), but can be solid in some cases.
- **Typical examples:** Galvanized screws, decorative hardware.
- **Best fit when:** Corrosion protection via plating or low-cost fasteners.
**8101.99 – Tungsten**
- **Defining trait:** Extremely dense and hard; used for high weight or wear resistance.
- **Typical examples:** Counterweights, heavy-duty industrial tools.
- **Best fit when:** Maximum mass per volume is needed (e.g., precision balancing).
**8102.99 – Molybdenum**
- **Defining trait:** High melting point and strength at elevated temperatures.
- **Typical examples:** High-temp furnace components, aerospace alloys.
- **Best fit when:** Extreme heat or high-stress environments.
**8104.90 – Magnesium**
- **Defining trait:** Lightest metal used in fasteners; prone to corrosion.
- **Typical examples:** Racing car parts, portable electronics.
- **Best fit when:** Maximum weight savings and low structural load.
**8108.90 – Titanium**
- **Defining trait:** High strength-to-weight ratio and excellent corrosion resistance.
- **Typical examples:** Medical implants, aerospace hardware.
- **Best fit when:** Need for lightweight, strong, and durable fasteners.
## Key differences
| Material | Density | Corrosion Resistance | Cost | Common Use Case |
|----------------|---------|------------------------|------|----------------------------|
| Iron/Steel | Medium | Low (unless coated) | Low | General-purpose |
| Copper | High | High | Med | Electrical, marine |
| Nickel | High | Very high | High | Harsh environments |
| Aluminium | Low | Medium | Med | Lightweight applications |
| Zinc | High | Medium (coated) | Low | Coated fasteners |
| Tungsten | Very high | Medium | Very high | Heavy counterweights |
| Molybdenum | High | High | Very high | High-temp use |
| Magnesium | Very low| Low | Med | Ultra-lightweight systems |
| Titanium | Medium | Very high | High | Critical performance apps |
## How to choose
1. Is weight the main concern? → 8104.90 (Magnesium) or 8101.99 (Tungsten)
2. Is corrosion resistance critical? → 7415.33 (Copper), 7508.90 (Nickel), or 8108.90 (Titanium)
3. Is high temperature involved? → 8102.99 (Molybdenum) or 7508.90 (Nickel)
4. Is cost the main factor? → 7318.1X (Iron/Steel) or 7907.00 (Zinc)
## Overlaps & pitfalls
- Tungsten and molybdenum both suit high-temp use; prioritize based on weight vs. strength needs.
- Zinc and copper can be used in similar environments but differ in conductivity and density.
- No option is vague, but "weight screws" may imply high mass—so tungsten or zinc may be preferred if mass is key.
- If multiple traits apply (e.g., light + strong), choose based on the **main function**: weight, durability, or cost